A responsive website responds to the characteristic of the device in which it is being viewed eg an iPhone or tablet. The site primarily changes size and shape (and a few other behaviours) so that it can be comfortably viewed in a ‘finger friendly’ context at a smaller size.
You should not have to pinch and squeeze a website on a mobile device. A full website being squeezed into a tiny space to display on a phone screen is NOT a responsive or mobile friendly website.
Some website owners believe that if they can see their website on a mobile phone (ie the desktop site squeezed to fit) then it is responsive.
This is totally wrong and their website traffic, visibility and sales/enquiries will suffer accordingly.
See more about mobile friendly website design.